Telescopic columns are used in numerous areas of technology. Using a telescopic column, an object or a device can be brought into different positions. In typical embodiments the telescopic column includes a plurality of round, or right-angled, or polygonal column elements lying one-inside-another, often configured tubular, which are retractable and extendable with respect to one another by a motor-driven mechanism. Respective directly adjacent tubes have a maximum extendability so that to maintain the stability a certain overlap of the tubes is always ensured. A distinction is made here between telescopic columns that are positioned on the ground and those that are attached to a ceiling. While the former are used, for example, in operating tables and make possible an upward and downward movement of the table, the latter are attached to the ceiling or a stand, for example, for movably securing X-ray machines. The X-ray machine is thus movable in height. In addition, another multiple-member arm can be attached between the telescopic columns, which multiple-member arm additionally makes possible a horizontal movement.
With the use of a steel cable, a belt, or a chain for moving the telescopic column there is in principle the risk of a breakage and an uncontrolled lowering, i.e., extending, of the telescopic column. In this case there is an acute risk of injury or damage. In this respect a safety mechanism is to be provided that reliably stops movement in the case of a break.